Conveyor-type, hydraulic-powered, material-spreading apparatus

ABSTRACT

Discloses a conveyor-type, hydraulic-powered, material-spreading apparatus comprising a material-storage hopper, a conveyor for conveying material from the hopper for spreading same and a hydraulic, power-transfer system comprising two double-acting, hydraulic cylinders in communication with and operatively connected to valves which control and direct hydraulic fluid under pressure to the hydraulic cylinders to drive the conveyor. Each hydraulic cylinder has two drive strokes per cycle, with each drive stroke approximating 160°, each hydraulic cylinder is 90° out of phase with the other, with positive drive resulting throughout the cycle. 
     Also discloses the hydraulic, power-transfer system described above for use in driving a conveyor for use with a material-spreading apparatus having a source of material to be spread, with such conveyor being disposed beneath the material for conveying same for spreading. 
     Also discloses a shock-absorbing device and limit stop for use with a member having a reciprocable element therein. Resilient bumper rings function as shock absorbers and limit stops upon abutment therewith of an end plate carried by the reciprocable element. 
     Also discloses a snap-action device for operative use with a reciprocable element in a member and with a reciprocating rod to reciprocate and slam the reciprocable element in the direction opposite to that being traveled by the reciprocating rod.

This is a Division, of application Ser. No. 634,032, filed 11/21/75 nowU.S. Pat. No. 4,023,689.

This invention relates to the art of material-spreading apparatuswherein and whereby a container such as a vehicle-mounted hopper isemployed for non-fluid material, and scattering means is employed toscatter the material. In particular, the invention relates to materialssuch as salt, sand, cinders, and the like, to be scattered and spread onroads and highways, or such materials for agricultural applications suchas fertilizers, and the like. The hopper is filled with the materialwhich is conveyed by a power-driven conveyor to a power-driven spinnerwhich scatters and spreads such material.

The present technology in the art employs a hydraulic motor which drivesan intermediate power-transfer system such as a worm-gear drive which inturn drives the conveyor drive shaft. Other examples of theintermediate, mechanical power-transfer systems employed are sprocketsand chains, or the combination of worm-gear and worm-type, unitizedspeed reducers. Such intermediate, mechanical power-transfer systemshave inherent power losses and achieve an overall machine efficiency inthe 60% to 62% range.

An object of the invention is to contribute to the solution of thisdiscussed problem of the art by providing a new, useful and advantageoushydraulic, power-transfer system which not only replaces the hydraulicmotor and its associated intermediate, mechanical power-transfer system,but also achieves an overall efficiency of 95%. The hydraulic,power-transfer system of this invention employs two double-acting,hydraulic cylinders with one of the hydraulic cylinders being 90° out ofphase with the other.

The amount of salt scattered and spread on roads and highways in thewintertime has engendered ecological concerns for the effects on theenvironment with the result that today minimal amounts of salt and otherchemicals are being scattered and spread on roads and highways in thewintertime. Moreover, without regard to ecological concerns, minimalamounts of sand and salt applied to roads and highways in the wintertimeproduce the beneficial effect of substantial costs savings. Possibleways and means employable to apply minimal amounts of salt or otherchemicals are: to close as far as possible the discharge gate beneathwhich the conveyor conveys the salt from the hopper to the spinner forscattering and spreading; to slow down the conveyor speed whilemaintaining the same vehicle speed and the same discharge openingbeneath the discharge gate; or to drive the vehicle at a fast rate ofspeed while maintaining the same conveyor speed and the same materialflow rate beneath the discharge gate.

A hopper filled with material compacts, especially after the hopper isfilled and then the vehicle mounting such hopper is driven. Therefore,to "break-away" such compacted load of material in the hopper, a torqueoutput of about twice the operating torque is required for the conveyorbar flights to "break-away" such compacted load of material in thehopper. The problem is that prior-art, hydraulic motors at start up havepoor lubrication and a tendency to stick; therefore, because of thisdescribed problem, the hydraulic motors to be utilized must be sizedlarge just to "start" the load. The hydraulic, power-transfer system ofthe invention, employing double-acting, hydraulic-cylinder drive todrive the conveyor, contributes to the solution of this discussedproblem of the prior art for the reason that the two double-acting,hydraulic cylinders are 90° out of phase with each other, for the reasonthat each hydraulic-cylinder piston has two drive strokes per cycle witheach drive stroke occupying approximately 160° with the result thatpositive drive throughout the cycle results, and for the reason thatthereby high-torque output is maintained throughout the speed range,from slow speed to high speed, with maximum torque output at close tozero RPM.

Conditions where the vehicles must be driven at a slow rate of speedoccur such as when the vehicles are employed for salting and/or sandingwhile going through a city or highly traffic-congested area and when thevehicles are employed both for plowing and salting and/or sanding at thesame time. Under these slow-vehicle speed conditions, the hydraulicmotors operate below their warranted speed of approximately 400 RPM withresulting damage or eventual damage, malfunction and breakdown of suchhydraulic motors. The described hydraulic, power-transfer system of thisinvention contributes to the solution of this discussed problem of theprior art for the previously delineated reason that high-torque outputis maintained through the slow to high speed range with maximum torqueoutput at close to zero RPM.

With the described hydraulic, power-transfer system of this inventionand with a minimum maintainable speed of close to zero RPM, an inifinitespeed adjustment is possible. The discharge gate can be left in apartially open position approximating 3 inches. All spreading speeds andamounts can be applied. Vehicle-operator comfort and safety resultbecause the operator does not have to stop his vehicle to adjust theposition of the discharge gate as road and storm conditions change.Discharge-gate damage is minimized, hydraulic pressure is lowered andsalt crystals scattered and spread remain intact and uncrushed formaximum deicing effectiveness on the highway.

When the material-spreading apparatus is utilized for seal-blotting andshoulder-fill operations, the conveyor is driven at high speed. Andbecause hydraulic motors must be sized large to overcome starting loads,high fluid flows are required for high conveyor speed. Since high-speedoperation of the conveyor requires high fluid flows, hydraulic pump sizeand reduction for practical application limit high-speed capacity. Thisinvention, employing the double-acting, hydraulic-cylinder drive todrive the conveyor, likewise contributes to the solution of thisdiscussed problem of the prior art because less hydraulic fluid isrequired for such hydraulic-cylinder drive to drive the conveyor at anygiven speed with the result that higher output speeds than conventionalmachines can be achieved without the use of different gearing or withoutthe use of larger hydraulic pumps. The reason for this is that lesshydraulic fluid flow in gallons per minute is required for the hydrauliccylinders of this invention than for hydraulic motors because thehydraulic cylinders employed in this invention displace approximately35% less hydraulic fluid than is displaced by the hydraulic motorsconventionally employed. With comparable hydraulic fluid flow from thehydraulic pump, the hydraulic cylinders of this invention can effectapproximately 50% greater speed of the conveyor than the prior-art,hydraulic-motor effected conveyor speed.

The hydraulic, power-transfer system employed in this inventioncontributes to the art in substantial savings realized in the operationof the material-spreading apparatus. In average, comparable operation, aconventional material-spreading apparatus will require 15 enginehorsepower or approximately 7.5 pounds of fuel per hour. In comparisonthereto, the hydraulic, power-transfer system employed in this inventionunder the same operating conditions will require only 10.5 enginehorsepower or approximately 5.25 pounds of fuel per hour for a netsavings of 2.25 pounds of fuel per hour or 0.4 gallon of fuel per hour.

It should be discerned and appreciated from the discussion of theproblems of the prior art and the contributions of this inventiontowards solving such discussed prior-art problems, and the contributionsof this invention to the spreader art, that the high overall efficiencyachieved by the described hydraulic, power-transfer system of thisinvention permits hydraulic-pump requirements to be reduced, therebydrastically reducing first cost to the user. It should be discerned andappreciated further, for reason of the advantageous operatingcharacteristics of the described hydraulic, power-transfer systememployed, that such system is suitable for a material-spreadingapparatus with attendant versatility for spreader use, and with lessmaintenance and adjustments required for such spreader use.

Accordingly, these objects and other objects of the invention should bediscerned and appreciated by reference to the detailed specificationtaken in conjunction with the drawings, wherein like reference numeralsrefer to similar parts throughout the several views, in which:

FIG. 1 is a perspective view of the material-spreading apparatus of theprior art;

FIG. 2 is a perspective view taken in the direction of the arrow "2" inFIG. 1;

FIG. 3 is a view of the hydraulic-cylinder drive of the invention at theleft sidewall of the hopper as viewed from the rear of the hopper;

FIG. 4 is a view of the hydraulic-cylinder drive of the invention at theright sidewall of the hopper as viewed from the rear of the hopper;

FIG. 5 is a view of the snap-action device;

FIG. 6 is a view taken in the direction of the arrows 6--6 in FIG. 5;

FIG. 7 is a view of the shock absorber and limit stop for the valvespool of the valve utilized in the invention; and

FIG. 8 is a schematic view of the invention showing the hydrauliccylinders and their respective pistons 90 degrees out of phase with eachother with drive imparted to the conveyor, and showing the respectivevalves associated with such hydraulic cylinders.

To facilitate the understanding of the invention, a nomenclature list isherewith provided:

1 generally refers to the prior-art, material-spreading apparatus

3 hopper

5 left sidewall of hopper 3

7 right sidewall of hopper 3

9 rear wall of hopper 3

11 front wall of hopper 3

13 gusset

15 materials chute

17 material deflector

19 material deflector

21 power-driven spinner

23 conveyor

25 bar flight of conveyor 23

27 chain of conveyor 23

29 hydraulic motor

31 worm-gear drive

33 hydraulic line

35 hydraulic line

37 discharge gate on rear wall 9

39 hand lever for discharge gate 37

41 channel iron

43 bracket

45 indication of bolting

47 transverse pivot mount

49 cylinder bracket

51 double-acting, hydraulic cylinder

53 piston

55 piston rod of piston 53

57 piston-rod end of piston rod 55

59 stub shaft

61 crank

63 drive shaft for conveyor drive sprocket

65 flange housing

67 bolt for flange housing 65

69 valve-rod crank

71 transverse pivot pin fixed to valve-rod crank 69

73 valve rod

75 threaded end of valve rod 73

77 snap-action, bifurcated mounting plate

79 lock nut on threaded end 75

81 spring-mount guide

83 transverse pin carried by guide 81

85 spring mount

87 compression spring on spring mount 85

89 spring-mount guide

91 transverse pin carried by guide 89

93 spring mount

95 compression spring on spring mount 93

97 valve-mounting bracket

99 4-way valve

101 valve housing of 4-way valve 99

103 valve spool of 4-way valve 99

105 reduced end portion of valve spool 103

107 clevis of spring mount 85

109 clevis of spring mount 93

111 cross pin

113 shoulder portion of clevis 107

115 shoulder portion of clevis 109

117 shock-absorbing housing

119 other end of valve spool 103

121 rubber-bumper ring carried by other end 119

123 rubber-bumper ring carried on housing 117

125 bumper plate carried on end 119

127 cap screw

129 high-pressure hydraulic line

131 low-pressure hydraulic line

133 Tee of line 129

135 elbow of line 129

137 valve-inlet port of valve housing 101

139 Tee of line 131

141 elbow of line 131

143 valve-outlet port of valve housing 101

145 hydraulic line communicating between ports 147 and 149

147 valve-cylinder port of valve housing 101

149 cylinder port of cylinder 51

151 hydraulic line communicating between ports 153 and 155

153 valve-cylinder port of valve housing 101

155 cylinder port of cylinder 51

In FIG. 1 of the drawings, reference numeral 1 generally refers to amaterial-spreading apparatus of the prior art. Such apparatus 1comprises a hopper 3, as shown, having, as directionally viewed from therear of hopper 3, left and right sidewalls 5 and 7, rear wall 9, frontwall 11 and gussets 13 to strengthen the hopper sidewalls 5 and 7.

Hopper 3 is appropriately disposed within the dump body of a dump truckor mounted on the chassis of a truck.

Fixed to and depending from the rear wall 9 of hopper 3 is a materialschute 15 at the end of which are material deflectors 17 and 19, and apower-driven spinner 21, all as shown. Disposed at the bottom of hopper3 is a conventional conveyor 23 having bar flights 25 carried by chains27 trained around a set of drive sprockets (not shown) in the rear and aset of idler sprockets (not shown) in the front. A hydraulic motor 29and worm-gear drive 31 are mounted, as shown. Hydraulic motor 29 isoperatively connected to worm-gear 31 and worm-gear drive 31 isoperatively connected to the drive sprockets to drive conveyor 23.

A conventional hydraulic pump (not shown) driven by the truck's engine,its power-take-off or some independent power source pumps hydraulicfluid under pressure to hydraulic motor 29 with communication betweenthe hydraulic pump and hydraulic motor 29 established by conventionalhydraulic lines 33 and 35. Appropriate conventional hydraulic controls(not shown) are interposed in the hydraulic system to effect and controldrive of the conveyor 23 in one direction or the reverse direction andto control the speed of conveyor 23.

For operation of the apparatus 1, hopper 3 is appropriately filled withmaterials such as salt, sand, cinders, and the like, to be spread onroads and highways, or such materials for agricultural applications suchas fertilizers, and the like. A discharge gate 37, mounted over an exitopening in the real wall 9 of hopper 3, as shown, is adjustably raisedor lowered by a hand lever 39 disposed and operatively connected todischarge gate 37, as shown. The amount of material scattered and spreadby spinner 21 depends upon the amount of material dispensed by conveyor23 from the hopper 3 to the materials chute 15 with such dispensedamount being controlled by the position of the discharge gate 37relative to its associated exit opening in the rear wall 9 of hopper 3and the operating speed of conveyor 23.

In FIGS. 3 and 4 of the drawings are shown the interrelated,hydraulic-cylinder drive of this invention mounted on the left and rightsidewalls 5 and 7, respectively, to drive conveyor 23, and whichhydraulic-cylinder drive replaces hydraulic motor 29 and worm-gear drive31.

Channel irons 41 are suitably fixed between the two rearward gussets 13on the left sidewall 5 and right sidewall 7, as shown. Fixed to andupstanding from channel iron 41 is a bracket 43 bolted to left sidewall5, as indicated at 45 and shown. A transverse pivot mount 47 pivotallymounts cylinder bracket 49 fixed to double-acting, hydraulic cylinder51. Piston 53, disposed and reciprocable within cylinder 51, isconnected to piston rod 55 whose piston-rod end 57 has a bearing mountedon the stub-shaft journal of stub shaft 59 fixed to a crank 61 which isfixed to the drive shaft 63 for the conveyor drive sprocket. Flangehousing 65, as shown, is fixed by bolts to the support structure and hastherein a bearing mounting drive shaft 63.

Valve-rod crank 69, fixed to stub shaft 59, has a transversely disposedpivot pin 71 pivotally mounting valve rod 73 whose threaded end 75 isengaged in a tapped hole (not shown) formed in the snap-action,bifurcated mounting plate 77. Accordingly, the operative length of valverod 73 may be adjusted relative to mounting plate 77 by inward oroutward movement, as required, of the threaded end 75 of valve rod 73relative to the tapped hole in mounting plate 77, and with suchresulting adjustment of the length of valve rod 73 fixed by thereafterappropriately engaging lock nut 79 on the threaded end 75 againstmounting plate 77.

A spring-mount guide 81, having two tranverse pins 83 fixed thereto, isthereby trunnion-mounted by such pins 83 being pivotally disposedthrough aligned holes formed in bifurcated mounting plate 77.Spring-mount guide 83 reciprocally receives freely therein a springmount 85 which carries and mounts thereon a compression spring 87.

A spring-mount guide 89, having two transverse pins 91 fixed thereto, isthereby trunnion-mounted by such pins 91 being pivotally disposedthrough aligned holes formed in bifurcated mounting plate 77.Spring-mount guide 89 reciprocally receives freely therein a springmount 93 which carries and mounts thereon a compression spring 95.

Fixed to and upstanding from channel iron 41 is a valve-mounting bracket97 that mounts a 4-way valve 99 whose valve housing 101 reciprocallyreceives therein a valve spool 103. Valve spool 103 extends beyond valvehousing 101 and has a reduced-end portion 105 that is received withinclevis 107 fixed to spring mount 85, and, in turn, clevis 107 isreceived within clevis 109 fixed to spring mount 93. A cross pin 111,disposed through aligned holes formed in reduced-end portion 105, clevis107 of spring mount 85 and clevis 109 of spring mount 93, affordspivotal-mounting relationship thereby.

As shown, the compression springs 87 and 95, mounted and carried ontheir respective spring mounts 85 and 93, are constrained by and betweentheir respective spring-mount guides 81 and 89, and by the respectiveshoulder portions 113 and 115 on their respective clevises 107 and 109.

As viewed more discernably in FIG. 5, as valve rod moves to its left andcarries bifurcated mounting plate 77 to its left, springs 87 and 95 willbe compressed between their respective spring-mount guides 81 and 89,and by their respective shoulder portions 113 and 115 of theirrespective clevises 107 and 109. At the position of maximum compressionof springs 87 and 95 represented by an imaginary line passing throughthe centers of pins 83, 111 and 91, and slightly beyond that position,reacting restoring vector forces from springs 87 and 95 provide thedrive means to reciprocate and slam valve spool 103 to the right in FIG.3 to occupy a position in the valve housing, that is shown in the bottomportion of FIG. 8, which would be with the valve spool to the extremeleft of the position of valve spool 103 shown in the bottom portion ofFIG. 8.

Shown in FIG. 7 is a shock-absorbing housing 117 fixed to valve housing101. The other end 119 of valve spool 103 extends into housing 117 andcarries a rubber-bumper ring 121. A similar rubber-bumper ring 123 iscarried on housing 117. Bumper plate 125 is carried on the end 119 ofvalve spool 103 by a cap screw 127 disposed through a hole formed inbumper plate 125 and engaged in a tapped hole formed in the end 119 ofvalve spool 103. It should be appreciated that in the reciprocation ofvalve spool 103 the rubber-bumper rings 121 and 123 function both asshock absorbers and limit stops upon the abutment of bumper or end plate125 with rings 121 and 123.

It should be appreciated that the hydraulic-cylinder drive shown anddescribed in FIG. 3 of the drawings is the same as thehydraulic-cylinder drive shown in FIG. 4. The difference is the factthat piston 53 in hydraulic cylinder 51 in FIG. 3 is 90° out of phasewith the piston of the hydraulic cylinder shown in FIG. 4.

Shown in FIG. 4 are the high-pressure, hydraulic line 129 from thehydraulic pump and the low-pressure, hydraulic line 131 that returns toa reservoir and thence to the hydraulic pump. High-pressure line 129communicates with a Tee 133 whose branch communicates in FIG. 3 with anelbow 135 providing communication for the high-pressure linecommunicating with valve-inlet port 137. Low-pressure, hydraulic line131 communicates with a Tee 139 whose branch communicates in FIG. 3 withan elbow 141 providing communication for the low-pressure linecommunicating with valve-outlet port 143. Hydraulic line 145 establishescommunication between valve-cylinder port 147 and cylinder port 149, andhydraulic line 151 establishes communication between valve-cylinder port153 and cylinder port 155.

In FIG. 8, the 4-way valve and hydraulic cylinder (top cylinder) shownon the top portion of the sheet represent the 4-way valve and hydrauliccylinder shown in FIG. 4; and the 4-way valve and hydraulic cylinder(bottom cylinder) shown on the bottom portion of the sheet represent the4-way valve and hydraulic cylinder shown in FIG. 3. The arrow on thevalve spool shown on the bottom portion of the sheet in FIG. 8 indicatesthe direction in which such valve spool is moving. The top cylinder isshown with its piston roughly halfway through its drive stroke with theposition of its associated valve spool corresponding thereto. The bottomcylinder is shown with its piston roughly at top dead center of its pushdrive stroke with the position of its associated valve spoolcorresponding thereto and being in the course of snap action.

Since double-acting, hydraulic cylinders are employed, drive can beimparted by push or pull of the piston: push when a cylinder and itspiston rod extend, and pull when a cylinder and its piston rod contrast.Each hydraulic-cylinder piston has two drive strokes per cycle with eachdrive stoke occupying approximately 160°. And since the hydrauliccylinders are 90° out of phase with each other, positive drivethroughout the cycle thereby results. As shown, during the cycle eachvalve-cylinder port alternates to drive the cylinder piston in onedirection of push and then after 180° in the opposite direction of pull.

When the springs 87 and 95 line up by an imaginary line passing throughthe centers of pins 83, 111 and 91, the corresponding positions of thepistons in their cylinders are 10° before top dead center in the one andbottom dead center in the other. Snap action of the springs 87 and 95theoretically should occur at top dead center or at bottom dead center.However, snap action occurs within the range of 5° before or after topdead center and similarly within the range of bottom dead center.

Having thusly described our invention, we claim:
 1. A snap-action devicefor operative use with a member having a reciprocable element thereinand a reciprocating rod to reciprocate and slam said reciprocableelement in a direction of travel opposite to the direction of travel ofsaid reciprocating rod, said snap-action device comprising a bifurcatedmounting plate, two spring-mount guides, two spring mounts and twosprings, said mounting plate mounting said spring-mount guides, saidspring-mount guides freely receiving said spring mounts, said springmounts carrying said springs, said mounting plate fixedly carrying saidreciprocating rod, and said spring mounts and reciprocable element beingjoined in pivotal relationship.
 2. A snap-action device in accordancewith claim 1, wherein said spring-mount guides carry transverse pins andwherein said mounting plate has aligned holes pivotally receiving saidtransverse pins by said mounting plate of said spring-mount guides.
 3. Asnap-action device in accordance with claim 1, wherein said springmounts carry clevises, and wherein said clevises and reciprocableelement have aligned holes pivotally receiving a cross pin for joiningsaid spring mounts and reciprocable element in said pivotalrelationship.
 4. A snap-action device in accordance with claim 1,wherein said spring-mount guides carry transverse pins, wherein saidmounting plate has aligned holes pivotally receiving said transversepins by said mounting plate of said spring-mount guides, wherein saidspring mounts carry clevises, and wherein said clevises and reciprocableelement have aligned holes pivotally receiving a cross pin for joiningsaid spring mounts and reciprocable element in said pivotalrelationship.